ATVs are popular multipurpose vehicles that are generally grouped into two categories: sport/high performance ATVs and utility ATVs. Sport ATVs are typically designed for high speed use, such as racing, and are thus lighter and faster than utility ATVs, which are used for activities such as hunting, camping and working. Sport ATVs are usually equipped with rear wheel drive and swing arm rear suspension, whereas utility ATVs are usually rear wheel drive with swing arm or independent rear suspension.
It is desirable to provide an ATV, particularly a high performance ATV, that is as light as possible, yet powerful and durable, with high quality ride characteristics. Many conventional ATVs provide some combination of power, durability and desirable ride characteristics, but often at the expense of added weight.
In ATVs having independent rear suspensions, the suspension system typically includes an upper control arm and a lower control arm, both of which generally include a mount in front of the drive axle centerline and a mount behind the drive axle centerline. In some designs, however, it is difficult to mount the upper control arm in front of the drive axle centerline because that space is occupied by other components.
For many high performance ATVs that employ independent rear suspensions, it is desirable to provide an anti-sway bar that effectively links the separate suspension units to one another for stability. As is known in the art, anti-sway (or anti-roll) bars provide a more level ride and inhibit the roll of the vehicle onto its suspension during cornering. Providing a mounting location for an anti-sway bar, however, adds additional weight, parts, and complexity to the vehicle. As such, it would be desirable to provide a lightweight, low part count, simple anti-sway bar for an ATV.
As is also known in the art, high performance ATVs, designed for improved handling and resistance to suspension bottoming, use higher ride frequencies than other ATVs designed for a smoother ride and slower maneuvering. Higher ride frequencies are a result of stiffer spring rate in the shock absorber springs. Such stiffer spring rates, however, may prevent the vehicle chassis from settling (or “riding in”) as much as desired for peak performance and handling.
Additionally, when riding a sport ATV on oval type tracks or during flat track racing, the ATV is typically turned in one direction (or is primarily turned in one direction). Accordingly, the load on one of the IRS units is substantially different from the load on the other IRS unit. As such, it would be desirable to permit independent adjustment of the IRS units to “tune” the suspension system to the requirements of the track for enhanced handling.